Regulating system



Nov. 7, 1933.

R. KELLER 1,933,858

REGULATING SYSTEM Filed April '7, 1932 UNITED STATES PATENT OFFICE 1,933,858 REGULATING SYSTEM Robert Keller, Ennetbaden, Switzerland, assignor to Aktiengesellschaft Brown Boveri & 010., Baden, Switzerland, a joint-stock company of Switzerland Application April 7, 1932, Serial No. 603,694, and in Germany April 22, 1931 6 Claims. (Cl. 171-229) This invention relates to improvements in reguvoltage of the generator within p dtermined lating systems and particularly to a system for m ts. regulating the output voltage of a generator by Another objectof the invention is to provide regulating the degree of excitation thereof, means associated with the excitation circuit of an Voltage regulating systems for electric generaelectric generator, which means will operate 60 tors from which the voltage delivered is to req i y p change of the generator u p in main within predetermined limits require the use coop With .Other means to C t o the eX- of a device which operates automatically. A pile citation of the generate! y Variation of the P of carbon disks connected into the excitation cirsure on a carbon p i t it f th x iter cuit of the generator and provided with means for of the ato 65 v rying the pressure on'the pile is amon the Objects and advantages other than those above more common means used heretofore for the pur- Set forth w ll be pp from the o wi depose of regulating the output voltage of such ge scription when read in connection with the accomerator. Such means may be electromagnets by De y drawing Which schematically illustrates which th pressure on th pile and hence th one embodiment of the present invention showing 70 sistance of the pile may be varied. such magnets a carbon pile resistance in the excitation circuit are frequently provided with vibrating contacts of a generat r, t action of the carbon p which make and breakacircuit continuously, thus ihg cooperatively Controlled y Changes in e affording a continuous supervision or control over current fl w in the excitation c rcui of the the output voltage of the generator. Such congenerator an y an induction d yp ulat r 75 tacts, however, have the disadvantage that sub- Op g in response o the Output Voltage of the stantially continuous arcing occurs thereon and ge a orthat the regulator, therefore, requires continuo s Referring more particularly to the drawing by attention to maintain the contacts in good operatcharacters of reference, the reference numeral ing condition. Further, carbon pile regulators 1 designates an electric line which is supplied so are not suitable for the regulation of large genby a generator comprising the armature winderators because the voltage cannot be regulated ings 2 a d t e excitation field Winding 3. he within sufficiently close limits and the regulator e c t W d 3 is c ected with an exover-shoots or passes beyond the predetermined citationmachine having a fi Winding '7 and limits in both directions of operation. Such overan. armature 8. The degree of excitation of the 5 ance in which system means are employed for conshooting or hunting of the regulator is very ungenerator 2,318 Controlled y Varying the amount desirable because the voltage will then vary withof pressure on and hence the amount of the in wide limits. Neither can such regulators be resistaiiw of the carbon p 6 which varies the used with high Speed generators because the excitation of field '7 and hence varies the effect tion of the regulator is too Slow of the exciter on the generator. It is, therefore, among the objects of the pres- The pressure on the carbon mm 6 15 produced 1 ent invention to provide avoltage regulating sysby Sprmg actmg on lever plVQtauy mounted at 13, and acting against an electrotem for generators employing a carbon pile resist magnet having the armature 16 thereof pivotany connected with the lever 12. The electromagnet tinuously securing exact adJustment of the preshas two coils and 18 wound and acting in Sure on the carbon pile and hence accurate opposite directions relative to each other, the

010i the resistance F coil 1'? being connected in series with an aux- Another o i of the 1mention is to provide a iliary field winding 21 of the exciter 7, a and a 45 Voltage regulating System for generators in Which current transformer 22 connected in the circuit a Carbon p resistance is employed and is p of the excitation winding 3 of the generator. vided with means to prevent over-shooting of the The coil 18 of the electromagnet is connected v l a limits 0 SCI-Called hu o the g with a source of current 26 such as the auxiliary lator. source for the generating station through a re- 50 Another object of the invention is to provide a sistance 27. The amount of resistance 27 in cirvoltage regulating system for large electric curcuit with coil 18 and current source 26 is varied rent generators in which a carbon pile resistance by a torque motor of any suitable character such is employed in conection with a torque motor operas the induction disk type instrument illustrated ated by the output voltage or an induction disk which comprises generally a contact segment 28 55 type regulator to secure regulation of the output mounted by means of a spring 29 on the shaft 30 of an induction disk or a wound rotor 31 upon which a torque is produced by coils 32 wound on suitable pole pieces 33, the coils 32 being connected with the terminals of the generator.

During the normal operation of the generator and its associated exciter, the resistance 27 is thus varied in response to the output voltage of the generator 2, 3 which results in variation of the current delivered from the auxiliary source of current 28 to the coil 18 directly in response to the output voltage of the generator. It will be understood that the induction regulator is also provided with suitable damping means and suitable means for returning the contactor 28 thereof to the original position, such means being well known in the art and not, therefore, herein illustrated and described.

When a disturbance, such, for example, as a short circuit on the line; occurs in the output circuit 0! the generator a current is induced in the excitation winding 3 thereof which operates to momentarily 'over excite the generator and, thereby, tend to maintain the generator in synchronism. Such induced current in the winding 3 also operates to induce a current in the secondary winding of the current transformer 22 which flows through the auxiliary field excitation winding 21 of the exciter machine and through coil 1'! of the relay 16. The flow of current through the winding 21 causes such winding to momentarily operate as a separately excited fleld winding cooperating with the main field excitation winding 7; and, as the coil 17 operates to oppose the action of coil 18, such flow of current through the coil 17 causes, in cooperation with the spring 11, the lever 12 to compress and thereby reduce the resistance of the carbon pile 8 with resultant increased excitation of the exciter machine, which operates to further increase the energization of winding 3 and thereby increase the tendency to maintain the generator in synchronism. The described flow of current through the coil 17 being of momentary duration only the resistance or the carbon pile would, unless otherwise controlled, be immediately again increased with resultant overshooting of the regulation limits in both direc tions and would, accordingly, cause hunting or the regulating system.

Such hunting is, however, use of a rotary type regulator such as shown in that the torque on the disk is varied in direct response to the output voltage of the generator. The amount of resistance 27 in circuit with coil 18 of the electromagnet is thus varied directly responsive to the output voltage of the generator. Coil 18 will thus oppose the action of coil 17 and will limit the movement of lever 12 which prevents such change of the resistance of the carbon pile as would cause over-shooting of the regulation limits. Hunting oi' the regulating system is, therefore, prevented by the rotary type regulator.

Although but one embodiment of the present invention has been illustrated and described, it is apparent to thou skilled in the art that various modifications and changes may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In a system for regulating the output voltage or a generator having an excitation machine connected therewith, a carbon pile connected with theexcitationmachineoithegenerator, alever prevented by the for varying the pressure on the said carbon pile, a spring acting on said lever, an electromagnet acting on said lever in opposition to said spring, said electromagnet having a plurality of coils arranged to act in opposition to each other on the armature thereof, means operable responsive to the rate of changes in the output current 0! said generator for energizing one of said coils, and means for controlling the degree of energization of another of the coils of said electromagnet to vary the action thereof in response to the output voltage of the generator.

2. In a system for regulating the output voltage of a generator by controlling the operation oi. an excitation machine therefor, a carbon pile connected with the excitation machine of the generator, a lever for varying the pressure on the said carbon pile, a spring acting on said lever, an electromagnet acting on said lever in opposition to said spring, said electromagnet having a plurality of coils arranged to act in opposition to each other on the armature, means operable responsive to changes in the output current 0! said generator for energizing one of said coils, a resistance connected with another of the coils of said electromagnet, a source 0! electric current connected with said another of the coils of said electromagnet and with said resistance, and means for varying the amount of said resistance in circuit with the coil and with said source of current in response to the output voltage of the generator.

3. In a system for regulating the output voltage of a generator by controlling the operation 01' an excitation machine therefor, a carbon pile connected with the excitation machine for the generator, a lever for varying the pressure exerted on the said carbon pile, a spring acting on said lever, an electromagnet acting on said lever in opposition to said spring, said electromagnet having a plurality of coils, means operable responsive to changes in the output load of said generator for energizing one of said coils, a resistance, a source of electric current connected with another of the coils of said electromagnet and with said resistance, and a rotary type regulator connected with the terminals of the generator to vary the amount of said resistance in circuit with the said another coil of said electromagnet in response to the output voltage of the generator.

4. In a system for regulating the output voltage of a generator, a carbon pile connected with the excitation machine for the generator, a lever for varying the pressure on said carbon pile, a spring acting on said lever, an electromagnet acting on said lever in opposition to said spring, said electromagnet having a plurality of coils, a source of electric current connected with one of the coils, means for controlling the amount of current supplied by said source in response to the output voltage of the generator, and means for energizing the other of the coils of said electromagnet in response to rate of changes in the output load of the generator.

5. In a system for regulating the output voltage of a generator, a carbon excitation machine for the varying the pressure on generator, a lever for said carbon pile, a spring acting on said lever, an electromagnet acting on said lever in opposition to said spring, said electromagnet having a plurality of coils arranged to act in opposition to each other on the armature, a source of electric current connected with one of the coils, means for controlling the amount of current supplied by said source in response to the output voltage of the generator, and a current pile connected with the transformer connected with the acting on said lever,

a source of electric current connected with one of the coils, means for controlling the amount of current supplied by said source in response to the output voltage of the generator, a current transformer connected into the excitation circuit of the generator, and an auxiliary winding connected in series with the secondary winding of said transformer and. the other of the coils of said electromagnet to energize the same in response to changes in theoutput of the generator.

ROBERT KELLER. 

